Noreudesmane sesquiterpenoids from Artemisia hedinii and their anti-inflammatory activities

Sesquiterpene lactones from Artemisia verlotorum and their anti-inflammatory activities

Seven new sesquiterpenoids (1-7) and 19 known analogues were isolated from the whole plant of Artemisia verlotorum. Their structures were determined by extensive analysis of 1D and 2D NMR and HRESIMS data, electronic circular dichroism (ECD) spectra, density functional theory (DFT) NMR calculations, and time dependent density functional theory (TDDFT) ECD calculations. The absolute configurations of 1, 3, 5 and 7 were confirmed by single crystal X-ray diffraction experiments. Compounds 1 and 2 possess a rarely reported 5/8-bicyclic skeleton, while both compounds 3 and 4 were uncommon iphionane-type sesquiterpenoids. Eudesmane sesquiterpenoids (5-17) reported in this study are all 7,8-cis-lactones, of which, compound 7 represents the first eudesmane sesquiterpene with an oxygen bridge connecting C-5 and C-11. All the compounds were tested in vitro for their anti-inflammatory activities in LPS-stimulated RAW 264.7 murine macrophages. Compound 18 showed a potent inhibitory effect on NO production, with IC50 values of 3.08 ± 0.61 μM.

Rare noreudesmane sesquiterpenoids from the fruits of Dysoxylum densiflorum

Seven rare noreudesmane sesquiterpenoids (dysoxydenones M-S, 1-7), including three 11,12,13-trinoreudesmanes, three 13-noreudesmanes and one spirovetivane-type sesquiterpenoid, along with two known analogues were isolated from the fruits of Dysoxylum densiflorum. The planar structures were elucidated by a combination of 1D, 2D NMR and HRESIMS analyses. Their absolute configurations were determined by combination of single-crystal X-ray diffraction, CD exciton chirality method and ECD calculation. All compounds were screened for anti-inflammatory activity on LPS-induced RAW 264.7 cells and IL-1β inhibitory activity.

Anti-inflammatory sesquiterpenoid dimers from Artemisia atrovirens

Eight new sesquiterpenoid dimers, artatrovirenolides A-H (1-8), along with three known analogues (9-11), were isolated from Artemisia atrovirens by using the LC-MS guided isolation. Compound 1 was a compound dimerized from a guaianolide and a 1,10-seco-guaianolide unit while others were from two guaianolide units. Their structures were established by comprehensive analysis of spectroscopic data, and their absolute configurations were determined by the aid of time-dependent density functional theory electronic circular dichroism (TDDFT ECD) calculation. Compound 8 showed anti-inflammatory effect in LPS-stimulated BV-2 microglial cells at 1 μM, while compounds 1, 2, 5, and 6 inhibited microglial inflammation at 10 μM.

Discovery of glucosyloxybenzyl 2-hydroxy-2-isobutylsuccinates with anti-inflammatory activities from Pleione grandiflora

Six new glucosyloxybenzyl 2-hydroxy-2-isobutylsuccinates, pleionesides A-F (1-6), along with two known compounds (7, 8) were obtained from the pseudobulbs of Pleione grandiflora (Rolfe) Rolfe. The structures and absolute configurations of new compounds were established by HRESIMS and NMR data, along with acidic hydrolysis and alkaline hydrolysis experiments. Compounds 1-6 were tested for their anti-inflammatory activities on LPS-induced BV2 microglial cells. Amoung them, 2, 4 and 5 showed moderate activities with IC₅₀ values of 73.4, 32.8 and 57.1 μM, respectively, compared with the positive control quercetin with an IC₅₀ value of 28.3 μM.